I shrunk them down to load quickly

Wild

is it supercharged?

No, just highly modified internals
and dual side draft carbs

No, just highly modified internals
and dual side draft carbs

ah just wondering, cuz thos pullys are huge haha

Those are what drives the propeller  

are they stromburg carbys? i was going to turbo a 76 celica with a stromburg 175 CD on it. very possible with those carbys.

and it looks mean as. if i opened the hood and saw that, i'd freak out, and then try to steal it when the owner was looking away.

are they stromburg carbys? i was going to turbo a 76 celica with a stromburg 175 CD on it. very possible with those carbys.

thats what they look like, i have the same carbs on my Trumph TR-7.

stu

Hi guys
    I wanted to take a second to thank "Wild" for hosting the engine pics for me, I admit to being a computer dufus. Thanks Wildgoody.
    The specs for the engine are listed under  "highperformance engine glitch" if you're interested.
    The carbs are strombergs and sikid-01 you are right they were off a TR-7. (CD175's) It's been a really neat but long drawn out project, check out the other thread for details.
    The guys on this site have been great with help diagnosing the glitch I've been fighting and I really appreciate it.
    As of last night and doing a pile of cam adjusting I'm still not getting full rpm but thrust tests are showing we are up to 100hp (approx) at 5000rpm.
    I listed the results of the experiment on cam retarding earlier but it looks like it got zorched by the hacker so I'll list it again here.

    The problem has been getting the engine to pull over
5000rpm. Goes to 5000rpm runs excellent but won't pull higher. From the advice I got here and a whole bunch or research I've diagnosed it to needing more cam. So I've ordered a cam. But while waiting for the cam I couldn't resist trying something different. Soooo

Test 1) -Engine was removed, all adjustments and
             systems verified correct.
           -Camshaft was retarded (1) tooth
Engine ran a little better, good throttle response under prop load, no additional rpm, no measurable power gain.

Test 2) -Camshaft retarded a total of (2) teeth
Engine runs very well, torque moved up 500-1000rpm, excellent mid range throttle response under p[rop load, ran a little cooler with extended (10-15min) wide open throttle. But no additional rpm (still max 5000rpm), but we were able to add another 1-2 degrees of pitch to the prop which indicates a slight power increase.
    Words of caution, I wouldn't recommend this setting for 4wd, it has moved the torque band up considerably and would not be a strong off road combination in my opinion. The other thing that is bothering me is I expected the engine to run badly as this is a pile of retard, I can't explain why it doesn't. It should by all rights run poorly and be overheating (from my experience on other engines). It does verify from the other link, one of the guys tried (1) tooth retard and I can say that does make things a little smoother and snappier.
    In the end I didn't get what I was looking for (more rpm) so the engine is out again waiting for the cam.

A special thanks agin to "Wild" and thanks to everyone for their input.

Zaggy

Thats good info, the carb conversion looks very cool. Strombergs were fitted as a performance mod to a lot of vehicles over here, either those or SUs. Better all round performance than Webers but not so much top end power. Do you have a thermostat on the end of that water gallery? Did you notice much difference experimenting with ignition timing? What octane fuel are you running? Sorry about all the questions but this a fascinating project.

No problem Rhinoman
    No we don't run a thermostat, we use a restrictor instead. Takes longer to warm up but eliminates a variable in testing. Ignition timing hasn't been that sensitive. If you look at the one pic you will see (2) coil packs, 1 on each side of the firewall. they are for the twin crank fire ignition system I designed. The coil packs have a built in 10 degree adv so total adv is 36 degrees on the main system. 28degrees on the start up, git it home system. About a 250rpm drop on the back up system. There is about 7 degrees adjustment in the system and it likes the most advanced but runs good through out the range. We run regular unleaded auto fuel (87 pump oct) thats why I've avoided big c/r. Bumping c/r adds around 2% hp per point bumped from my experience so I felt I could get away with out it.
    Interesting note for the guys who go real high in the mountains and stuff...the CD type carbs I am using are inherently altitude compenstaing, thats why I picked them. Rhinoman is on the money that these carbs work well mid range but give a little to the webers up high. But I wanted their ability to automatically compenstate for altitude. *****Note the CD175's I'm running are probly 1 size to big for the application*** for a driver like the engine I'm building for my daughters rag I woulld highly recommend going to CD150's.
    This cam thing has still got my curiousity though. I felt sure I could get the rpm I wanted with the stock cam and it's really bothering me, especially after playing with cam settings....more and more I'm bothered by the results. I have noticed there are at least (3) different upper cam gears any one got any insight?

Zag

I understand why you use the Strombergs for an aircraft engine. When I played with the cam timing on my old race bike I got similar results, I didn't see any real improvement to the top end either. What I suspect is that you are moving back the inlet closing point which tilts the torque curve towards the top end but at the same time moving back the inlet opening point which is detrimental to cylinder filling and is cancelling out any gains. A similar thing is taking place with the exhaust timing. The long duration camshaft should fix all that

Hi Again
 Ã‚    I sure hope you are right on the cam. That's why I've been experimenting to get the right answer (hopefully the first time). The altitude compesting also helps with the airboat. The variations in humidity and heights arn't a problem.
Zag

Side benefit, according to my research the Strombergs can't get carb ice because there is no true venturi.

Zag

I'm not sure about that carb icing can be a definite problem with SUs so I would have thought that the same would apply to Strombergs. I've only got SUs now so I can't compare the two but as I recall they're very similar in design.

Hi Rhinoman

    Wow, you're the first I've run into that has encountered carb ice with this style carb. Got any more details?
    The Bing carb is used extensively on ultra light and light a/c and their documentation allows them to go with no carb heat. Limbach uses the CD Strombergs and operators tell me they've never run into it.
    I've also checked extensively with the guys I ussed to ice race with and they though I was nuts.

    Was yours fuel supply side icing (blocking the fuel getting to the carb) or icing in the air intake side?

Zag

Hi Rhinoman

    Wow, you're the first I've run into that has encountered carb ice with this style carb. Got any more details?
    The Bing carb is used extensively on ultra light and light a/c and their documentation allows them to go with no carb heat. Limbach uses the CD Strombergs and operators tell me they've never run into it.
    I've also checked extensively with the guys I ussed to ice race with and they though I was nuts.

    Was yours fuel supply side icing (blocking the fuel getting to the carb) or icing in the air intake side?

Zag

Zaggy
You know any preasure drop can cause icing and if if flys it should be able to be preheated if necessary. Strombergs can Ice but rarely do and when they do it is when the prop speed is up and you shut the throttle. usually if you are paying attn you will feel the stumble and be able to throttle back up before it dies. the problem is it often happens when you are busy on final and you find you are gonna be a bit short so you bump the throtle and the Ice has partially blocked the fuel jet. this causes a lean condition and the engine can die.
Bad cause you were gonna be short before, now you are short and hope there are no trees.

make it heat capable  even if you don't use it.
Thanks
Wayne